A definitive answer for the first one: Adaption is where a species adapts to its environment by putting use to certain parts of the body. Almost all organisms must adapt for their environment, when us humans wear a jacket we adapt to the environment by deflecting the cold. The fennec fox has adapted by growing large ears to hear under the desert ground, and claws that are specially designed for digging through the ground to make burrows and hunt subterranean animals.
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PCD would make concieving children difficult because the fallopian tubes cannot push an egg out in order for the sperm to fertilize it